The present invention is directed to the production of sulfur containing organosilicon compounds by a new process which can be carried out in a simple, safe and problem free manner from readily available starting materials without the formation of toxic by-products and with a practically quantitative progress of the reaction.
There is known a process for the production of bis-(alkoxysilylalkyl)-oligosulfides from the corresponding alkoxysilylalkyl halogenides by reacting with alkali metal oligosulfides, preferably in alcoholic solution (Belgian Pat. No. 787,691 and related Meyer-Simon U.S. Pat. No. 3,842,111 as well as Thurn U.S. Pat. No. 3,873,891). The alkoxysilylalkyl halides in turn are obtained from the halosilylalkylhalides in conventional manner by alcoholysis. The entire disclosures of Meyer-Simon and Thurn are hereby incorporated by reference and relied upon.
There has also been proposed in Pletka application Ser. No. 730,726, filed Sept. 24, 1976 and now U.S. Pat. No. 4,072,701, a process for the production of bis-(alkoxysilylalkyl)-oligosulfides from halosilylalkyl halides by reaction with an alcohol, alkali metal hydrosulfide and sulfur in a so-called one kettle reaction wherein hydrogen sulfide is formed as by-product so that a part, one mole, of the sulfur added is not utilized for incorporation into the molecule of the oligosulfide. The hydrogen sulfide cannot be recovered in practice, but also cannot be released to the atmosphere. The entire disclosure of the Pletka application is hereby incorporated by reference and relied upon.
The problem of the present invention was to eliminate this disadvantage and to find a process giving as close to quantitative yield as possible without forming toxic or environmentally undesirable by-products.